New Delhi, Oct. 17: The Union health ministry today banned the manufacture and sale of a drug called letrozole to treat infertility in women, four years after its own drug regulators had waived safety studies and relaxed rules to approve the medicine.

In a statement notifying the ban, the ministry said the drug is likely to involve risk to human beings and safer alternatives are available.

The drug has been used to treat breast cancer in post-menopausal women for years in several countries, including India. The health ministrys drug regulators approved letrozole for infertility therapy in April 2007 after an Indian company, Sun Pharmaceutical Industries, conducted clinical trials with the compound. They ignored a warning by the original manufacturer, Novartis, that said the drug should not be given to pre-menopausal women because of its health risks.

Documents released by the health ministry in 2008, in response to queries by CPM leader Brinda Karat, have suggested that drug regulators had waived safety studies and relaxed rules so that approval was given after trials on 55 women, instead of 100 as required under rules.

Some gynaecologists who have prescribed letrozole for infertility estimate that several thousands of women across the country may have received this medicine over the past four years. One infertility specialist said she was surprised by the ban announced today.

This is really disturbing. Why did our drug authorities approve the medicine in the first place? said Reeta Biliangady, clinical director of a fertility clinic in Bangalore, who estimates she has prescribed letrozole to nearly 300 women over the past four years. Maybe we need an Anna Hazare to watch over drug regulators, Biliangady said.

When the health ministry documents indicating irregularities emerged, Sun Pharmaceutical officials said the company had fulfilled all regulatory requirements for approval of the drug, as was reported in The Telegraph on September 8, 2008.

A senior drug regulator claimed that the safety studies were waived because other studies had already been done outside India on letrozoles effectiveness to treat infertility. The regulator also said the number 100 in a clinical trial was not sacrosanct.

Neither company officials nor drug regulators were available for comment today.

A wrong has been undone today, said Chandra Gulhati, the editor of the Monthly Index of Medical Specialities, India, an independent drugs journal which had first exposed the illegal promotion of letrozole for infertility in India nearly eight years ago.

In 2005, Novartis, the original manufacturer of the compound, after discussions with a Canadian health agency, issued a cautionary note warning doctors that the use of letrozole for infertility could lead to problems in embryos or foetuses.

There have been post-market reports of congenital anomalies in infants of mothers exposed to (letrozole) for the treatment of infertility, the company said in its statement.

The health ministry has not explained the circumstances that led to its decision to ban letrozole for induction of ovulation with immediate effect.

An infertility specialist in Pune said she began prescribing letrozole after company officials assured doctors in 2007 it had been approved by drug regulators.

How can doctors be expected to know whats going on in the drug approval process? asked Bharati Dhorepatil, the chairperson of the clinical research division of the Federation of the Obstetrics and Gynaeological Societies of India.